November 25, 1922] 



NA TURE 



707 



a period of four years allowed between hydrographic 

 phenomena and herring catches. For a period of fifty 

 years it has been possible to show a relation between 

 the range of tide at Aberdeen and the productivity of 

 the herring fishery of the east coast of Scotland. The 

 curves representing tidal data and herring catches show 

 periods in which they tend to parallelism and to con- 

 vergence", but until this periodicity is understood and 

 can be foreseen the result will be of little use com- 

 mercially. Good year-classes can be referred to the 

 activities of Atlantic water, which have been shown by 

 Pettersson to depend upon the periodic variation of 

 lunar influence, but more definite knowledge is required 

 as to the time, intensity, and direction of invasions of 

 Atlantic water into the North Sea. This is particularly 

 illustrated by the conditions which are held to have 

 produced the 1907 year-class, which gave the rich fishery 

 on the east coast of Scotland in icjro. The wide-spread 

 occurrence of the rich year-class of 1904 which was 

 found in the Gulf of St. Lawrence and in practically all 

 waters of north-west Europe suggests that a study of 

 the hydrographic conditions of the North Sea alone 

 is insufficient for a full understanding of the factors 

 which determine the wealth of the different year- 

 classes. 



Although the production of gocd year-classes has the 

 greatest influence on the fishery in that these year- 

 classes give a herring population sufficiently large to 

 yield a succession of large catches throughout the season, 

 or a number of seasons, the migrations of the herrings 

 have an effect which is considerable and they may in 

 some cases bring about the foimation of new fisheries or 

 the non-existence of others. Pettersson has shown how 

 the great Baltic herring fishery of the Middle Ages coin- 

 cided with a maximum activity of Atlantic waters, due 

 to the greatest possible tidal influence of the moon and 

 sun, and, also how the present Baltic fishery fluctuates 

 in a period of eighteen to nineteen years. These fluctua- 

 tions are noticeable chiefly in shoals of adult fish, and, 

 in our waters, for the shoals off East Anglia and the 

 winter herrings of the east coast of Scotland, they have 



been found to alternate with those of the Baltic fishery. 

 The composition and nature of the shoals about the 

 Shetlands this year point to migrations which have 

 followed the most recent invasion of Atlantic waters, 

 with which has coincided the lateness of the appearance 

 of the Northumberland July shoals in 1920 and 1921 

 and of the shoals fished from Yarmouth in September 

 1921. Before we can hope to understand this periodicity 

 in migrations and the difference from year to year in 

 the arrival of our shoals a much more comprehensive 

 knowledge of the hydrography of the North Sea and of 

 the factors controlling the movements of the waters of 

 the North Atlantic is required. Further, the publica- 

 tion of the statistics relating to the fishery in a form 

 which will allow of their examination as to where and 

 when the catches were made is desirable. 



That the poor quality of the herrings and the early 

 maturity of the younger year-classes have coincided 

 with one another and with the presence of large quan- 

 tities of Atlantic water cannot be taken as solving the 

 problem of their occurrence. Neither does the poor 

 liver yield from Norwegian cod, which, in some years 

 at least, coincided with large numbers of young fish 

 among adult cod and with Atlantic water activity, 

 throw any further light on what must be regarded as a 

 physiological problem awaiting investigation, and one 

 which cannot be considered as explained by a reference 

 to a possible scarcity of copepcds. 



The problem of the fluctuations in our herring fishery 

 is not one which can be solved by a consideration of one 

 or two isolated set of phencmena. That the activity of 

 Atlantic w-ater has a connexioVi with periodicity in the 

 fishery and with the production of good year-classes 

 suggests a possible way of approach. It is a problem 

 which demands the attention not only of the zoologist 

 and the hydrographer, but also of the physiologist and 

 probably that of the astronomer. Further, it must not 

 be forgotten that the men engaged in the fishery and 

 the industries connected therewith are concerned more 

 about the fluctuations from year to year than those 

 which are spread over much longer periods. 



The Nebraska Tooth. 



By W. P 



AT the meeting of the Zoological Society on Novem- 

 ber 7, Prof. Elliot Smith exhibited a cast of 

 the now famous Nebraska tooth, which is regarded 

 by American palaeontologists as representing a new 

 genus and species of the human race — Hesperopithecus 

 haroldcooki. This tooth — a "second upper molar" 

 — differs, we are assured, on one hand from that of 

 any known anthropoid apes, and on the other from 

 any of the primitive types of man yet discovered. 



Prof. Elliot Smith is in agreement with this interpre- 

 tation ; and presented fresh evidence in its support, 

 furnished him by Prof. Osborn. This evidence included 

 the results of radiographing the tooth, together with 

 the teeth of a chimpanzee and Piltdown man. But 

 these, it must be admitted, were unconvincing pictures, 

 since they failed to demonstrate the features they were 

 designed to show. 



The teeth of the Piltdown man, it will be remembered, 

 showed a large pulp-cavity placed above the level of 



NO. 2769, VOL. I io] 



Pycraft. 



the alveolar border of the jaw, as in modern man'; 

 wherein, however, the cavity is smaller. But the 

 Piltdown teeth, in this regard, differ as much from the 

 teeth of Neanderthal man, wherein the pulp-cavity 

 was of great size, and evidently developed at the 

 expense of the roots. Sir Arthur Keith has called 

 such teeth " taurodont." They are peculiar to men 

 of the Neanderthal type. The Piltdown teeth, like 

 those of the modern man, are of the " cynodont " 

 type. This fact, it may be predicted, will come to 

 have an additional significance in the near future. 



Dr. A. Smith Woodward, in the discussion which 

 followed Prof. Elliot Smith's remarks, reaffirmed his 

 original belief — expressed at the time when the dis- 

 covery of the Nebraska tooth was first announced, 

 and set forth in Nature of June 10 (vol. 109, p. 750) — 

 that this tooth was more probably that of one of the 

 primitive, extinct bears (Hyaenarctos), than of some 

 primitive member of the primates. Prof. Osborn 



